Overview of LEO Satellite Systems

1 1999 International Symposium on Advanced Radio Technologies1 Overview of LEOO verview of LEOS atellite SystemsSatellite SystemsChristopher ReddingChristopher ReddingInstitute for Telecommunication SciencesInstitute for Telecommunication SciencesNational Telecommunications and Information AdministrationNational Telecommunications and Information AdministrationBoulder, COBoulder, International Symposium on Advanced Radio Technologies2 Overview Characteristics of LEO Systems Emergence of LEO Technology Classification of LEOs LEO Systems Iridium Government Involvement Conclusion1999 International Symposium on Advanced Radio Technologies3 Characteristics of LEO Systems Anytime.

2 Anywhere Blends cellular and Satellite technologies Satellite Terrestrial Gateways 500 - 2000 km orbit Below Van Allen Belts Fiber-like propagation delay Voice and data capabilities Hand-held multi-mode phones1999 International Symposium on Advanced Radio Technologies4 Emergence of LEO Technology Lower propagation delay in LEO vs GEO toll quality voice circuits now possible IP over Satellite Use of Ka frequency band vs C and Ku smaller antennas Advances in Satellite technology ACTS, MILSTAR inter- Satellite links (ISL) on-board processing switching, routing.

3 Store-and-forward improvements in Satellite manufacturing process1999 International Symposium on Advanced Radio Technologies5 Emergence of LEO Technology Spot beam frequency reuse Lower launch costs Multiple satellites per launch New launch sites in China and Russia Need for global wireless services voice data Bandwidth demand data applications Vocoder technology toll quality voice at 2400 bps1999 International Symposium on Advanced Radio Technologies6 LEO versus GEO Less propagation delay for LEOs More LEOs required for global coverage Single LEO failure will not result in lostcommunication Less exposure to Van Allen Belt radiation Inter- Satellite links versus bent-pipe Jitter Ka band Rain attenuation1999 International Symposium on Advanced Radio Technologies7 LEO Subscriber Growth1999 International Symposium on Advanced Radio Technologies8 Classes of LEOs Little LEOs Non-voice services Orbcomm LEO One Final Analysis Big LEOs Voice plus limited data services Iridium globalstar Constellation Communications Broadband LEOs High-speed data plus voice Teledesic SkyBridge1999

4 International Symposium on Advanced Radio Technologies9 Little LEOsSystemOrbcommLEO OneFinal AnalysisCompanyOrbcomm, Orbital SciencesLEO OneFinal Analysis, GeneralDynamics Info SystemsService Typesmessaging, paging, e-mailmessaging, paging, e-mailmessaging, e-mail, file transferVoice (kbps)---------------Data kbps kbps kbps uplink24 kbps downlinkTBDO rbit Altitude (km)8259501000No. of Satellites484838No. of Orbit Planes387 Earth Stations10207 Mobile Uplink 148-150 MHz148-150 MHzVHF/UHFM obile Downlink137-138 MHz, 400 MHz137-138 MHz137-138 MHzFeeder Uplink148-150 MHzVHF/UHFF eeder Downlink137-138 MHz, 400 MHzVHF/UHFISL NoNoNoService Date1996200220011999 International Symposium on Advanced Radio Technologies10 Big LEOsSystemIridiumGlobalstarConstellation CommunicationsCompanyMotorolaLoral, Alcatel, QualcommOrbital Sciences, BellAtlantic, RaytheonService Typesvoice, data, fax, paging,messagingvoice, data, fax, paging,messagingvoice, data.

5 FaxVoice (kbps) / / (kbps) Altitude (km)78014102000 Number of Satellites664846 Orbit Planes688 Earth Stations15 - 20100 - 210 TBDB eams / Satellite481624/32 Footprint Dia. (km)47005850 TBDM obile Uplink (MHz)1616 - (L-band)1610 - (L-band) - 2500 (S-band)Mobile Downlink (MHz)1616 - (L-band) - (S-band)1610 - (L-band)Feeder Uplink (GHz) - (Ka-band) - (C-band) - (C-band)Feeder Downlink (GHz) - (Ka-band) - (C-band) - (C-band)ISL Yes (4)NoNoService Date1998200020011999 International Symposium on Advanced Radio Technologies11 Broadband LEOsSystemSkyBridgeTeledesicCompanyAlcat el, LoralMotorola, Boeing, MatraMarconi, Gates, McCawService Typesinternet access, voice, data,video, videoconferencinginternet access, voice, data,video, videoconferencingVoice (kbps)TBD16 Data (kbps)2,000 uplink20,000 downlink2,000 uplink64,000 downlinkOrbit Altitude (km)14691375 Number of Satellites80288 Number of Orbit Planes212 Earth Stations200 TBDB eams / Satellite ~5064 Footprint Diameter(km)

6 30001412 Feeder Uplink (MHz)Ku-band28,600 - 29,100 (Ka-band)Feeder Downlink (MHz)Ku-band18,800 - 19,300 (Ka-band)ISL NoYes (8)Service Date200120041999 International Symposium on Advanced Radio Technologies12 LEO Orbital Altitudes1999 International Symposium on Advanced Radio Technologies13 Orbcomm Operational since 1996 Trailer tracking services for trucking fleets Two-way messaging technology beingmarketed to US government and military GPS hand-held Satellite communicatorintegrates Orbcomm technology forworldwide messaging Internet capabilities Planned IP messaging gateway for HTTP.

7 XMLand UDP messaging functions SMTP/POP3 and global wireless e-mail1999 International Symposium on Advanced Radio Technologies14 Orbcomm Constellation1999 International Symposium on Advanced Radio Technologies15 LEO One Provides near real-time store-and-forwardmessaging tracking and fleet management monitoring and remote control two-way messaging emergency services transaction processing Finished development of Satellite antennasystem and gateway station1999 International Symposium on Advanced Radio Technologies16 Final Analysis 36 satellites in 6 orbital planes at 51E 2 satellites in 83E plane Three ground stations completed Terminals Remote Terminal Messaging Terminal File Transfer Terminal Services offered real-time near real-time store and forward1999 International Symposium on Advanced Radio Technologies17 globalstar 36 globalstar satellites in space as of August17 launch Fleet of 48 will be in orbit by December 4 per launch Commercial service to start October 10 Employs bent-pipe vs ISL proven technology Coverage concentrated between +/- 70E Phone manufacturers

8 Ericsson, Qualcomm and Telital1999 International Symposium on Advanced Radio Technologies18 globalstar Constellation1999 International Symposium on Advanced Radio Technologies19 Constellation Communications Data oriented Initial phase will have single equatorial orbit of11 satellites Coverage between +/- 23 E Service to begin in 2001 Additional 35 will be deployed Five per orbit in seven circular inclined orbits Global service in 20031999 International Symposium on Advanced Radio Technologies20 Teledesic Combines efforts with Celestri (1998) Motorola becomes prime Teledesic partner Internet-in-the-sky Portable vs mobile 45 cm antenna directional Lockheed Martin launch provider Motorola - constellation's system provider1999 International Symposium on Advanced Radio Technologies21 Teledesic Constellation1999 International Symposium on Advanced Radio Technologies22 SkyBridge Protects GEO Systems in the Ku-band throughfrequency re-use concept Proven technologies reduce cost and overallrisks of system gateways use ATM-based interfaces supports Internet protocols "bent-pipe" system

9 Terrestrial-based switching Ku-band frequency lower hardware costs due to mature technology less signal attenuation due to rain than Ka frequencies1999 International Symposium on Advanced Radio Technologies23 Iridium Voice network operational since November 98 On-board processing and ISLs Separate voice and data channels 2400 bps voice: low latency 2400 bps data: error-free delivery packet switched data channel expected in 99 Types of connections Iridium to/from PSTN Iridium to Iridium1999 International Symposium on Advanced Radio Technologies24 Iridium Constellation1999 International Symposium on Advanced Radio Technologies25 Iridium system Overview1999 International Symposium on Advanced Radio Technologies26 Iridium Call Scenario1999 International Symposium on Advanced Radio Technologies27 Iridium in the News Iridium gets US Military as First Big Customer(1/26/98)

10 The World's First Global Satellite Telephone andPaging Company Starts Service (11/1/98) Iridium CEO opts to leave (6/14/99) Iridium cuts staff, stock suffers (6/14/99) Iridium cuts prices to boost subscriber base(6/21/99) Motorola calls for help with I